Part 2 (1/2)

Not only should the greatest care be paid to the condition of the cans and milk-pails, but all dippers, strainers, and other utensils that come in contact with the milk must be kept equally clean Cloth strainers, unless attended to, are objectionable, for the fine mesh of the cloth retains so much moisture that they become a veritable hot-bed of bacterial life, unless they are daily boiled or steahly render vessels bacteria-free with the conveniences which are generally to be found on the far and sterilizing the milk cans at the factory

~Germ content of milk utensils~ Naturally the number of bacteria found in differentwill be subject to great fluctuations; but, nevertheless, such deter a scientific foundation for practicalstudies may serve to indicate the relative importance of the utensils as a factor in milk contamination

Two cans were taken, one of which had been cleaned in the ordinary hile the other was sterilized by steahly cleaned and special precautions taken to avoid raising of dust; the fore milk was rejected Milk drawn into these two cans showed the following ger

Steamed pail 165 28-1/2 Ordinary pail 4265 23

Harrison[6] has sho great a variation is in the bacterial content in milk cans The utensils were rinsed with 100 cc of sterile water and nu water erm content was 442,000; in cans washed in tepid water and then scalded--the best farm practice--54,000, and in cans carefully washed and then steamed for five minutes, 880

Another method used by the writer is to wash the utensil with 100 cc

sterile ater, using a sterile swab to remove dirt Then repeat the process twice orplate cultures fro data were obtained from three such deters Total No

I II III bacteria

7,800,000 1,450,000 49,000 9,299,000 283,000 43,400 35,000 361,400 1,685,000 105,000 61,400 1,851,400

~Infection of lected but considerable factor of infection is that which is attributable to the bacteria which are present in the udder and which are re process An examination of the fore milk, i

e, the first few streaenerally reveals a very anisms in the fore milk[7] Not infrequently will this part of the milk when drawn under as careful conditions as possible, contain several score thousand organisms per cc If successive bacterial deter, as shown in the following experiment, a marked diminution is to be noted after the first portion of the milk is removed:

_Bacterial content at different periods of s

milk cc cc cc cc

Expt 1 6,500 1,700 475 220 75 5 Expt 2 8,100 1,650 400 240 50 10

By some observers it has been claimed that it is possible to secure absolutely sterile s but this is rarely so It is quite probable that such reported results are due to the fact that too small quantities of milk were used in the examinations and so erroneous conclusions were drawn This er proportion of the organisms found in the fore milk are present in the lower portion of the udder and iven to the structure of the udder, it is readily apparent that infection will be greater here than above

[Illustration: FIG 8 Sectional view of udder showing teat withexterior with the milk cistern Milk sinuses are mostly shown in cross section interspersed and below the secreting tissue (Moore and Ward)]

The udder is coland cells_) held in place by fibrous connective tissue Ralandular structure are numerous channels (_milk sinuses_) that serve to convey the milk from the cells where it is produced into the _milk cistern_, a common receptacle just above the teats This cavity is connected with the exterior through the htly closed by the circular sphincterout The mucous membranes of the milk duct and cistern are naturally moist The habits of the animal render it i at the end of the teat and there is no mechanical reason why bacteria cannot readily find their way along the anisms are adapted to this kind of an environment, ideal conditions exist for their multiplication, as moisture, warmth and suitable food supply are present The question arises how far up into this organ is penetration possible? Within late years nuanisms in the upper portion of the udder in contact with the secreting tissue[8]

These investigations prove that bacteria are distributed throughout the whole of the udder, although nuion of thetissue than in the lower portion

Ward's conclusions are ”that lands of a healthy udder is sterile It may however, immediately become contaminated by the bacteria which are normally present in the smaller milk ducts of the udder”

~Nature of bacteria in forethe nue, and of those which do appear many occur at only occasional intervals Moore[9] in the examination of 9 udders found 20 different forms, and of these only 3 species predominated, all of which proved to be micrococci Streptococci have also been quite frequently reported Freudenreich[10] found theto both the liquefying and non-liquefying class

Peptonizing[11] and spore-bearing[12] species have also been reported as well as gas-producing[13] fors are, however, due in all probability to accidental invasion

Most investigators report the absence of the distinctively lactic-acid group of organisin of bacteria in udder~ There is no question but that ain access fro and intestinal types have such a favorable opportunity for introduction from outside and are so unlikely to have come directly from the body of the animal, that the external source of infection is in of the cocci that are so generally found in the upper portion of the udder is questionable The stateans are bacteria-free, but the studies of Ford[15] seeans, res and cats contained living organisms Others have reported similar results in which cocci have been found[16] very sis increase the probability that the origin of this type is from the blood The persistence of certain species in the udder for rowth of so[17] has shohere cows are not reatly increased

~Artificial introduction of bacteria into udder~ If bacteria are capable of actually developing in the udder proper, it ought to be possible to easily demonstrate this by the artificial introduction of cultures In a number of cases[18] such experiments have been iosus_, lactic acid bacilli and others In no case has it appeared evident that actual growth has occurred, although the introduced organis nuer coccus isolated from the fore milk failed to persist for more than a few days when thus artificially introduced This failure to colonize is indeed curious and needs explanation Is it due to unsuitable environermicidal influence of the milk?